Air cleaner



Jan. 3, i950 D. B. BRowNE -ETAL 2,493,335

AIR CLEANER Filed March 16', 1944 2 Sheets-Sheet 1 f A ttorneyzt Jan. 3, 1950 v D.`B. BRWNE ET Al. A 2,493,335

AIR CLEANER Filed March 16, 1944 2 Sheets-Sheet 2 Patented Jan. 3, 1950 AIR CLEANER Donald Bennion Browne, Harpenden, and Kenneth Ernest Buckman, Dunstable, England, assgnors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application March 16, 1944, Serial No. 526,663 In Great Britain March 17, 1943 This invention relates to air cleaners such as are used on internal combustion engines.

The invention is particularly concerned with air cleaners of the impingement-wetting type, that is to say those in which the air impinges on the surface of a liquid, usually oil, and thereby carries some of the oil into a mesh to wet the same.

In such cleaners the solid particles which are caught in the wet mesh are carried into the liquid container as the liquid drains down. They form a sludge in the sump of the container, which eventually raises the liquid level to an inoperative height. For this reason an overflow compensator is fitted, so as to maintain a constant liquid level.

According to the invention an air cleaner of the type hereinbefore referred to is characterised in that the compensator is located within the oil container and in that overflow from the container can pass into the compensator through a centrally disposed apertured means at the upper end of an upwardly directed reentrant chamber.

The invention will now be described with particular reference to the accompanying drawings wherein:

Figure 1 is a view partly in vertical section and partly in elevation of an air cleaner constructed in accordance with the invention; and

Figure 2 is a sectional plan view taken on the plane indicated by the line 2-2 in Fig. 1 looking in the direction of the arrows.

As illustrated in the drawing the improved air cleaner comprises an outer casing 3 and a concentric inner casing 4 which is filled with a filter body of superposed layers 5 of porous or fibrous material, the bottom of the said inner casing 4 being apertured to provide for circulation in the known manner. The vertical wall of the outer casing 3 is provided with an intermediate shoulder 3a and the lower portion of the said outer casing 3 constitutes the oil container 3b.

Disposed within the oil container 3b is an overow or liquid lever compensator 6. This compensator 6 co-operates with an annulus 1 which is provided in a horizontal flanged portion thereof with apertures 1a. The lower section of the compensator 6 is also formed with an upwardly extending reentrant chamber 6a having in the upper end thereof a hole which is bounded by an arcuate anti-splash lip 6b, said hole being concentric with the main assembly spindle 8 so that an annular space 9 obtains between the periphery of the assembly spindle 8 and the lip 6b.

The upper portion of the compensator 6 is formed with an arcuate anti-splash rim 6c which 2 Claims. (Cl. 18S-15) abuts the underside of the bottom of the inner casing 4 and this rim 6c is formed at equidistantly spaced intervals with notches 6d as and for a purpose to be specified hereinafter. The upper portion of the compensator 6 is surrounded by an annular baille l0 provided with spaced elongated slots Illa.

The container 3b is filled with oil to the level indicated so that the ledge constituted by the inner surface of the shoulder 3a is below the normal oil level.

Air passes into the cleaner by way of the inlet 3c and is directed downwardly through the annular space 3d on to the surface of the oil where it becomes wetted before passing upwardly through the filter material 5 and away through the outlet 3e.

Dust and dirt trapped by the lter material 5 and by the oil subsequently fall into the bottom of the container 3b.

As dust and dirt accumulate in the bottom of the container 3b oil overflows from the container 3b by way of the holes 'la in the annulus 1 and the annular space 9 between the lips 6c at the upper end of the reentrant chamber 6a and the spindle 8 into the compensator 6 whilst the air displaced from the compensator 6 due to the overflow described escapes by way of the notches 6d afore referred to, the annular space between the neck of the compensator 6 and the baiile l0 and the elongated slots Illa in the said baille l0.

It will be seen that the arrangement provides for the maintenance of a constant liquid level and that owing to the communicating means between the container and the compensator being located adjacent to the centre of the cleaner, undue displacement of the oil due to tilting is avoided.

Further, since the main bulk of the compensator is below the level of the oil in the main liquid container the effect when the whole cleaner is tilted is to produce a lower effective oil level than would be the case where the compensator not fitted for it will be apparent that if no compensator were fitted, there would be in fact an additional volume of oil equal in bulk to the displacement of the compensator which would flow into the new tilted position thus resulting in a higher oil level than is the case with the compensator.

If desired, the invention may be applied to an air cleaner which incorporates a cleaner of the cyclone type as disclosed in the specification of British Letters Patent No. 550,292 in the name of The AC-Sphinx Sparking Plug Company Limited and others.

We claim:

1. In an air cleaner including a casing having a body of wetted porous or fibrous lter material above a liquid containing sump and an air inlet passage for flow of air under the lter body and over the liquid in the sump; a liquid level compensator centrally located in the sump and immersed in the liquid therein comprising an annular chamber having a centrally positioned reentrant lower and inner wall and an inwardly inclined outer and top wall, the portion of the reentrant lower and inner wall at the level at which liquid is to be maintained in the sump being near the axis of the chamber and being apertured at such level to provide for overflow at such level, and the inwardly inclined outer andvtop wall extending from below to above such level.

2. In an air cleaner including a casing having a body of wetted porous or brous filterv material above a liquid containing sump and an air inlet passage for flow of air under the lter body and over the liquid in thesump; a-liquid level compensator centrally located in the Vsump and immersed in the iliquid therein comprising an an- `nularchamber having'a centrally apertured reentrant lowerl and inner wall and an inwardly inclined outer and top wall, the top portion of the REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 890,996 Mullen June 16, 1908 973,775 Goodrich Oct. 25, 1910 2,239,731 Neumann Apr. 29, 1941 FOREIGN PATENTS Number Country Date 550,292 Great Britain Jan. 1, 1943 

